DE4227800A1 - THROMBUS RELEASING TREATMENT DEVICE - Google Patents

Description

The present invention relates to a thrombus-releasing Treatment device according to the preamble of the patent claims 1 and in particular a device for dissolving a thrombus formed in a blood vessel Using a thrombus solvent and ultrasound waves.

Vascular diseases occur in Europe and the USA, e.g. B. Atherosclerosis and thrombosis, frequent and with increasing Tendency on. Also in Japan take thrombotic, ischemic Heart disease, e.g. B. Cerebral and myocardial infarction tion, due to the changing eating habits to and are now one of the two most common causes of death chen (besides cancer). To treat such an ischemic Heart disease requires a thrombectomy. The Thrombectomy or vascular grafting makes it difficult significant physical intervention and is therefore special for older patients who are increasingly suffering from this disease suffer, not cheap. One in a cerebral blood vessel or a cardiac coronary artery thrombus causes infarction of the cerebral or myocardial Cells, if not an immediate thrombectomy becomes. In the former case in particular there is a serious one an endangerment of life or the danger of serious Aftermath if the thrombectomy is not timely he follows. It is therefore imperative to use the throm perform bectomy as soon as possible.

Thrombolysis treatments, e.g. B. PTCR (percutaneous trans luminary cardiac recanalization), "intravenous continuous infusion" (a method of supplying a large amount of a thrombus dissolving agent with high concentration over a longer period), "intraartial infusion" (a procedure to deliver a thrombus-releasing agent into an artery  carotid via a catheter) and PTCA (percutaneous translumi nare cardiovascular plastic) are increasingly being used as quick, effective Thrombosis treatments are valued as compared to a surgical operation or the like. one less drastic intervention for the patient. With these Treatment methods become a Kathe for example at PTCR which is inserted into a coronary artery, and a thrombus Solvent quickly gets into the coronary artery in the area of the thrombus, taking the positions of the blood vessel and the catheter by using an x-ray Contrast agents are monitored by radiography. With the PTCR method, however, the recanalization rate is Blood vessel is small, and there is also the problem of X-ray exposure. With the "intravenous continuous infu sion "is the recanalization rate of the blood vessel relatively high, but here the side effect occurs, that the blood through the large amount of thrombus-releasing agent difficult to clot. In addition, according to the PTCA Method the inner wall of the blood vessel using a balloon elastic stretched catheter. So despite a high "Blood vessel recanalization rate" the risk of again caught occurrence of thrombosis.

Recently the mode of action of thrombus-releasing Reinforced by both feeding the thrombus-releasing agent by "intravenous continuous infusion" as well as external irradiation of the thrombus with Ultra uses sound. Because with this procedure the dosage thrombus-releasing agent can be reduced Reduction in side effects reported (Medical Electronics and Bioengineering, vol. 26, page 536, 1988). But this method also minimizes the managed amount of thrombus dissolving agent desirable. For this purpose, a therapeutic ultrasound wave effectively radiated to the thrombus area and progress of the thrombus dissolution process are monitored so that after  no excess after the complete dissolution of the thrombus Means more is fed. Furthermore, the quantitative Control of thrombolytic treatment beneficial to to be able to carry out a precise, effective treatment.

As described above, the thrombus-relieving treatment is which both relate to the administration of a thrombus-releasing agent supports as well as ultrasonic wave radiation, thereby advantageous because it is basically a high therapeutic Has effects with only a few side effects. To this The therapeutic ultra must be used to maximum advantage sound wave on a thrombus area as the affected area be directed effectively and precisely, and the treatment progress must be monitored so that no excess thrombus-releasing agent is supplied. Preferably done treatment with precise specification of the therapeutic Steps.

It is an object of the present invention to have a thrombus releasing treatment device with simultaneous feeding of a thrombus-releasing agent and ultrasound radiation Provide an ultrasonic wave in effective Way directed and the progression of the thrombus-releasing Treatment can be monitored so that a high thera Achieved therapeutic effect and the amount of thrombus-releasing Can be reduced to a minimum by means of which again to minimize side effects. This task is at a treatment device according to the preamble of Claim 1 or 2 or 6 according to the invention by the in its respective characteristic part contained characteristics solved.

The present invention therefore sees a thrombus-releasing one Treatment device in which a thrombus resolved by applying a therapeutic ultrasound wave to a thrombus-affected area of a blood vessel is directed,  into which a thrombus-releasing agent is injected, whereby this device comprises: an ultrasound Emitter for radiating a therapeutic ultrasound wave into the thrombus area, an ultrasound probe for Acquisition of tomographic image data from the body of a Patient, a first ultrasound imaging device for visual output of those supplied by the ultrasound probe tomographic image data, one inserted into the blood vessel introduced catheter, one intended for the catheter Ultrasound converter for the acquisition of tomographic image data from inside the blood vessel and a second ultrasound imaging device for the visual output of the Ultra sound converter supplied tomographic image data.

According to the present invention, a thrombus-releasing treatment device provided at in addition to the basic structure of the Ultra described above sound transducer with a function to detect one of the Ultrasonic probe outgoing ultrasonic wave is executed and the further via a position detection device to detect a position of the catheter by an output signal from the ultrasound probe Ultrasonic transducer is processed as well as via an Direction to display the result of the position detections device on a screen of the first Ultra sound imaging device.

In this case, the ultrasound transducer is preferably made from at least one band-shaped piezoelectric element, which is arranged in the longitudinal direction of the catheter. Two of the Dimensions of the piezoelectric element, i. H. its thickness, its length in the circumferential direction of the catheter or its Length in the axial direction of the catheter correspond a frequency of the ultrasonic wave to achieve the tomo graphic image data of the blood vessel and a frequency of ultrasound wave used by the ultrasound probe to Er  capture of the tomographic image data from the body of the Patient. It is advantageous if the remaining dimension, d. H. Thickness, length in the circumferential direction or in the axial direction of the catheter, with the frequency of that of the ultrasound emitter radiated ultrasonic wave match.

Furthermore, the present invention can be in addition to the above described basic structure of a computing device for loading include a value that corresponds to the effect of the Thrombolysis treatment based on ultrasound corresponds to the tomographic image data supplied by the converter, and a device for switching off the radiation of the therapeutic ultrasound wave through the ultrasound radiator if the value calculated by the computing device has reached a predetermined value. The can continue lying invention a device for turning off the one injecting thrombus dissolving agent into the blood vessel include if the value calculated by the computing unit has reached the specified value.

In the first ultrasound imaging device, for example a B-mode tomographic image as the tomographic image the inside of the patient's body the thrombus area is recognizable. The second ultrasound Imaging device gives a tomographic sectional view of the Blood vessel and shows the respective state of the thrombus-releasing treatment. Accordingly, the therapeutic ultrasound wave to strengthen the treatment effect on the thrombus area be, so that with sufficient dissolution of the thrombus a unnecessary administration of thrombus-releasing agent and thus unwanted side effects can be prevented. That means, that the position of the thrombus resulting from the simple B-mode ultrasound image is not easy to spot, precise is determinable, so that an excessive influence of thera peutischen ultrasonic wave is avoided.  

The value representing the thrombus therapy effect, i.e. H. "The recanalization rate" is calculated Ways. Will the radiation of therapeutic ultrasound wave turned off by the ultrasound emitter or if continue the injection of the thrombus-releasing agent in the thrombus ends when a predetermined value is reached treatment can be stopped automatically, as soon as the thrombus is sufficiently loosened. As a result, lets yourself a more effective treatment with less side achieve effects.

Furthermore, according to the present invention Ultrasound wave from the ultrasound probe through the Ultra sound transducer recognized the position of the catheter, d. H. From stand and direction relative to the ultrasound probe Processing of the demodulation signal detected; this one The rapid result is shown on the first ultrasound picture output device and the tomographic image of the The patient's body superimposed, which means with certainty can be determined whether the catheter is correctly in the Thrombus area is introduced.

In this case, if any two of the dimensions of the in Arranged longitudinally of the catheter and the Ultra acoustic transducer-forming piezoelectric element, d. H. its thickness, its length in the circumferential direction of the catheter or its length in the axial direction of the catheter is chosen in this way are that they generate the frequency of the ultrasonic wave the tomographic image data of the blood vessel and the Frequency of the ultrasound wave that the ultrasound probe is used for Generation of the tomographic image data of the inside of the body the patient draws, correspond, so the piezo electrical element perform two functions, d. H. to the a a monitoring function of the tomographic image of the blood vessel and, secondly, a reporting function Lich the position of the catheter, d. H. the position of the  Ultrasonic transducer itself. Both of these functions combined, so the number of ultrasonic transducers forming piezoelectric elements can be reduced, whereby a simple, small ultrasonic transducer ver can become real, which is easy on Have catheter attached. When setting the remaining Dimension of the piezoelectric element, d. H. the thick, the length in the circumferential direction of the catheter or the length in Axial direction of the catheter, according to the frequency of the Ultrasound wave emitted by the ultrasound emitter can the ultrasonic transducer take over the function of the beam Position of the therapeutic wave from ultrasound monitor spotlights.

The invention will be described in more detail below with reference to the drawings explained. Show it:

Fig. 1 is a structural view of a treatment apparatus according to the first thrombuslösenden exporting approximately of the present invention;

Fig. 2 is a view of the core area of Fig. 1;

Fig. 3 is a view for explaining a sound transducer in an ultra piezoelectric ele ments used;

Fig. 4 is a view of the structure of the core region according to the second embodiment of the present invention;

Fig. 5 is a structural view of a treatment apparatus according to the third thrombuslösenden exporting approximately of the present invention;

Fig. 6 is a perspective view of an ultrasonic transducer according to the fourth embodiment of the present invention;

Fig. 7 is a structural view of a thrombuslösenden treatment apparatus according to the fifth embodiment of the present invention approximately;

FIG. 8 is a view of the structure of the core area shown in FIG. 7;

FIG. 9 is an enlarged view of the core area according to FIG. 8;

Fig. 10 is a view showing another example of the installation position of an ultrasonic probe of an ultrasonic emitter;

Figure 11 is a view of an additional example of the installation position of an ultrasonic probe in an ultrasonic radiator.

Fig. 12 is a view showing another arrangement of the ultrasonic radiator;

Fig. 13 is a view showing still another arrangement of the ultrasonic radiator;

Fig. 14 (a), 14 (b) and 14 (c) various drivers wave form of the ultrasound radiator;

Fig. 15 examples of display outputs of a tissue image and a B-mode-blood vessel image according to the fifth embodiment of the present invention; and

FIG. 16A and 16 (B) Examples of the screen output of a tissue image.

Fig. 1 shows the structure of a thrombus-dissolving treatment device according to the first embodiment of the present invention. This thrombus-releasing treatment device comprises an ultrasound emitter 20 for external radiation of a therapeutic ultrasound wave into a thrombus area, an ultrasound wave 21 for the external monitoring of a thrombus position, a catheter 22 which is inserted percutaneously into the thrombus position, an ultrasound transducer 23 which is located on the peripheral surface of the distal End of the catheter 22 is attached, and a system housing 25th The system housing 25 is in communication with the ultrasound emitters 20 of the ultrasonic probe 21 and the ultrasound transducer 23 in order to make use of the ultrasonic probe 21 sensing th tomographic image data and the detected by the ultrasonic transducer 23 tomographic image data of a cross section through a blood vessel visible to display the position of the ultrasound transducer 23 and to regulate an ultrasound wave to be emitted to the thrombus.

Specifically, this means that the ultrasonic radiator 20 (for. Example, 450 kHz), a therapeutic ultrasonic wave having a frequency of 50 kHz to 1 MHz from outside a patien th P to a thrombus 31 radiates when one of a radiator control circuit 38 in the system housing 25 remote control signal is received. The catheter 22 contains an injection tube for the thrombus-releasing agent, which is connected to a control (not shown) or a controller for the injection of the thrombus-releasing agent in the system housing 25 . In this way, the thrombus 31 is loosened and treated in that both the thrombus-bus-dissolving agent is supplied and the therapeutic ultrasound wave is irradiated.

The ultrasound probe 21 has a vibrator arrangement which is formed from a plurality of ultrasound vibrators arranged in series and which is in close contact with the body surface of the patient P. The body interior of the patient P is scanned in sectors (the scanning scope is a fan-shaped section shown in FIG. 1) when control signals are transmitted from an external probe control circuit 26 in the system housing 25 in predetermined relative delay time intervals. The frequency of the incoming ultrasound wave transmitted by the ultrasound probe 21 is e.g. B. 5 MHz. The ultrasound wave transmitted by the ultrasound probe 21 is reflected by a tissue in the interior of the patient P. The reflected wave is received by the same ultrasound probe 21 and converted into an electrical signal (e.g. an echo signal). The echo signals detected by the corresponding vibrators of the ultrasonic probe 21 are sent to an external probe input circuit 27 in the system housing 25 and are delayed by the same relative delay time intervals as during the transmission. Then the echo signals are processed, e.g. B. subjected to synchronization / addition, wave demodulation and amplitude compression in a tissue imaging system processing circuit 28 and passed to a tissue screen 29 for outputting a B-mode image of the tissue inside the body. The external probe control circuit 26 , the external probe receiving circuit 27 , the tissue imaging system processing circuit 28, and the tissue screen 29 form a first ultrasound imaging device 41 .

The catheter 22 is inserted at the position of the thrombus 31 formed in a blood vessel 30 of the patient P. The ultrasonic transducer 23 attached to the distal end of the catheter 22 is used together with an internal probe control circuit 34 and an internal probe receiver circuit 35 in the system housing 25 to carry out the first function, ie to record the tomographic image data of the blood vessel 30 . This means that the ultrasonic wall 23 carries out a so-called "radial scanning" in the circumferential direction of the catheter 22 . The ultrasonic transducer 23 contains a multiplicity of strip-shaped piezoelectric elements which are arranged in the circumferential direction of the catheter. These piezoelectric elements are sequentially selectively driven by the internal probe control circuit 23 to perform an electronic radial scan. A signal detected by the ultrasound transducer 23 is processed by a processing circuit 36 of the B-mode blood vessel imaging system and sent to a B-mode blood vessel screen 37 for displaying a radially directed sectional image of the blood vessel 30 . The state of dissolution of the thrombus 31 at this position can be determined by observing this sectional image of the blood vessel 30 . The internal probe control circuit 34 , the internal probe receiver circuit 35 , the processing circuit 36 of the B-mode blood vessel imaging system and the B-mode blood vessel screen 37 form a second ultrasound imaging device 42 . The frequency of the ultrasonic wave transmitted and received by the ultrasonic transducer 23 is different from that of the ultrasonic probe 21 and is, for. B. 20 MHz.

In its second function, the ultrasonic transducer 23 serves as a search device. Specifically, this means that the ultrasonic transducer 23 receives an ultrasonic beam going from the ultrasonic probe 21 and converts it into an electrical signal. This signal is amplified and demodulated by a viewfinder reception circuit 32 in the system housing 25 and sent to a catheter position detection circuit 33 . The catheter position detection circuit 33 detects the position of the catheter 22 , ie the distance between the ultrasound probe 21 and the ultrasound transducer 23 , and its direction on the basis of an output signal from the seeker reception circuit 32 . The results of the distance or direction thus detected are sent to the tissue imaging system processing circuit 28 and are added phase locked to the signal from the external probe receiving circuit 27 so as to be output on the tissue screen 29 , thereby representing the B-mode image of the Tissue are overlaid inside the body.

According to another embodiment, an ultrasound transducer 23 can be connected to a viewfinder control circuit. In this case, the viewfinder control circuit operates such that an ultrasound pulse signal (ie, an upward broken arrow) is generated out of phase with the transmitter / receiver system of an ultrasound probe 21 ; This ultrasound pulse signal is received by the ultrasound probe 21 in order to be able to output the position of the ultrasound transducer 23 together with the B-mode image of the tissue inside the body on a tissue screen 29 .

The ultrasound transducer 23 still performs a third function, ie it receives a therapeutic ultrasound wave (ie an interrupted arrow pointing downwards) from the ultrasound emitter 20 . A signal detected by the ultrasound transducer 23 , which corresponds to the therapeutic ultrasound wave emitted by the ultrasound emitter 20 , is amplified and demodulated by a therapeutic ultrasound receiver circuit 39 and sent to a radiation position detector circuit 40 . The radiation position detector circuit 40 detects the radiation position of the therapeutic ultrasonic wave based on the strength of the received therapeutic ultrasonic wave. The result in this regard is output on the tissue screen 29 for overlaying the image of the body-internal tissue by means of the tissue image system processing circuit 28 .

The treatment method according to this embodiment is now described.

• 1) The catheter 22 is operated while observing the position of the thrombus 31 in the B-mode image of the inner tissue on the tissue screen 29 so that the ultrasonic transducer 23 is displaced.
• 2) Similarly, the visible on the fabric screen 29 position of the ultrasonic transducer 23 is inserted so assumed that they sammenfällt with the position of the thrombus 31st The sectional image of the blood vessel 30 with the thrombus 31 is observed simultaneously on the B-mode blood vessel screen.
• 3) An injection controller (not shown) for the thrombus-releasing agent is controlled so that the thrombus-releasing agent (eg urokinase or t-PA) is injected from the catheter 22 into the blood vessel 30 . The emitter control circuit 38 causes the ultrasound emitter 20 to emit a therapeutic ultrasound wave in the direction of the thrombus 31 . The ultrasound emitter 20 is shifted while observing the B-mode image on the tissue screen 29 in such a way that the therapeutic ultrasound wave is directed precisely onto the thrombus 31 .
• 4) If it is determined on the basis of the blood vessel sectional image on the B-mode blood vessel screen 37 that the thrombus 31 has dissolved sufficiently, the injection controller for the thrombus-releasing agent interrupts the further supply of the thrombus-releasing agent via the catheter 22 .

The ultrasound transducer 23 is described on the basis of the perspective view according to FIG. 2. An injection hose 43 for the thrombus-releasing agent is inserted into the catheter 22 and the ultrasound transducer 23 is connected to the corresponding components of the system housing 25 via a cable 44 . The ultrasonic transducer 23 in this embodiment consists of a vibrator arrangement in which a multiplicity of strip-shaped (rectangular) piezoelectric elements 24 are arranged on the circumference of the catheter in such a way that their longitudinal extent runs parallel to the axis of the catheter 22 .

FIG. 3 is an enlarged perspective view of a strip-shaped piezoelectric element 24. With reference to FIG. 3, reference numeral 45 designates the internal probe control circuit 34 , the internal probe receiver circuit 35 , the finder control circuit 32 and the therapeutic ultrasound receiver circuit 39 according to FIG. 2.

A thickness Ld, a length Ll and a width Ls of the strip-shaped element 24 correspond to an ultrasonic frequency for the radial scanning for the acquisition of tomographic image data of the blood vessel cross-section within the scope of the first function of the transducer 23 , a frequency (ie the frequency of the from the ultrasound probe transmitted ultrasound wave) of the ultrasound transducer 23 as the viewfinder, wherein the second function of the ultrasound transducer 23 be, and a frequency of the therapeutic ultrasound wave CUS, which is received by the transducer 23 according to the third function.

According to the first embodiment, the ultrasound frequency for the so-called "radial scanning", the frequency of the ultrasound wave transmitted by the ultrasound probe 21 and the frequency of the therapeutic ultrasound wave is 5 MHz, 20 MHz or 450 MHz. Due to the relationship λ / 2d between a size d (each of the three dimensions thickness Ld, length Ll or width Ls) of the piezoelectric element 24 in a certain direction and a wavelength λ that in that direction at a speed of 3000 m / s, 2700 m / s or 1800 m / s emitted ultrasonic wave, the thickness Ld, the width Ls or the length Ll is set to 0.075 mm, 0.27 mm or 2 mm. It should be noted here that these dimensions can be changed to a certain extent, even if the frequency remains the same, provided that the piezoelectric material to be used is changed (which is available with different strength properties).

As described above for the first embodiment, the number of piezoelectric elements and the total volume can be reduced or reduced, since the ultrasonic transducer formed by arranging only one type of piezoelectric element can perform all of the three functions described above, so that a cable 44 to Connection of the system housing 25 and the ultrasonic transducer 23 is sufficient, whereby the structure is simplified. As a result, the catheter 22 can be easily inserted into a blood vessel with this ultrasound transducer 23 , unlike a catheter which is made with three separate ultrasound transducers to perform the three functions described above.

FIG. 4 is a perspective view of an ultrasonic transducer 50 according to the second embodiment of the present the invention. If the therapeutic ultrasound wave is not a convergence wave, its radiation position need not be monitored since it can hardly differ from the thrombus. Consequently, in the second embodiment, the components of the thrombus-releasing device according to FIG. 1 are omitted with regard to monitoring the radiation position of the therapeutic ultrasound wave, and the ultrasound transducer 50 is connected to this device.

For each one of a plurality of strip-shaped piezoelectric elements 51 which form the ultrasonic transducer 50 , it applies that its thickness Ld can be set according to the ultrasonic frequency for radial scanning, while either its length Ll or its width Ls corresponds to the frequency of that of an ultrasonic probe 21 radiated ultrasonic wave can be selected. Accordingly, this ultrasonic transducer 50 can be manufactured more easily.

The first and second embodiments are examples of one Ultrasonic transducer consisting of vibrators for electronics cal scanning is formed. However, it is also possible to use a mechanically scanning vibrator with only a strip-shaped piezoelectric element leads (its length, width and thickness to the target frequencies according to the respective functions), whereby this  strip-shaped piezoelectric element in rotation ver is set.

Fig. 5 shows the structure of a thrombus-releasing treatment device according to the third embodiment of the prior invention. The most critical case further aggravated by thrombosis is ischemic heart disease, caused by a blood flow legion or a blood flow occlusion in a coronary artery. Since the coronary artery in particular is surrounded by ribs, it is difficult to direct a convergent, therapeutic ultrasound wave from the outside onto a thrombus located in a coronary artery. For this reason, in the third embodiment, an ultrasonic transducer 60 , which is arranged on a catheter 22 according to the second embodiment, has a function for emitting a therapeutic ultrasonic wave. The ultrasound transducer 60 includes a viewfinder (which can also be referred to as a transponder) 62 , a vibrator arrangement (which serves as an internal ultrasound probe) 63 and a therapeutic vibrator 64 which - starting from the distal end - in the order mentioned on the peripheral surface of the catheter 22 are arranged. The viewfinder 62 and the therapeutic vibra tor 64 are designed annular.

In the third embodiment, an ultrasound beam with a center frequency of 3.75 MHz is emitted by an ultrasound probe 21 and received by the viewfinder 62 . That is, the resonance frequency of each piezoelectric vibrator of the finder 62 is set to, for example, 3.75 MHz. A received signal corresponding to the ultrasonic beam received by the finder 62 is sent to a finder-receiver circuit 65 for amplification and demodulation, formed into a square wave by means of a wave shaper 66 and to a catheter position detector circuit 33 for determining the position (distance and direction relative to the ultrasonic probe 21 ) of the seeker 62 .

The catheter position detector circuit 33 includes a counter. When the ultrasonic probe 21 emits the ultrasonic beam when receiving a drive signal from the external sensor control circuit 26 which receives Kathederpositions- detector circuit 33 a control pulse of the external probes control circuit 26 that triggers the clock counting by the counter. The counting up by the counter continues until a reception signal from the finder 62 arrives. The position of the finder 62 is calculated from the value determined by the counter. The position data of the finder 62 is transferred to a tissue imaging system processing circuit 28 . At the same time, the counter is reset and waits for the next position detection of the finder 62 . The positional data of the distal end of the catheter 22 , which has been input to the tissue image system processing circuit 28 , is output on the tissue screen 29 in the form of a "focus" or a marker and is superimposed on the B-mode image of the internal body tissue.

To detect the position of the viewfinder 62 , it can be connected to a viewfinder control circuit, which in turn can be connected to the wave former 66 according to FIG. 5. This means that for an input signal in the waveform shaper 66, the viewfinder control circuit is activated and the viewfinder 62 is caused to emit an ultrasonic beam having a frequency of 3.75 MHz, which corresponds to the reception frequency of the viewfinder 62nd Since this ultrasound beam is received by the ultrasound probe 21 , this results in the position of the finder 62 on the tissue screen 29 being able to be output after the signal processing for generating the tomographic image of the tissue inside the body.

In the third embodiment, the vibrator arrangement 63 generates an ultrasound beam with a center frequency of 25 MHz and outputs a sectional image of the blood vessel 30 on the blood vessel B mode screen 37 . The therapeutic vibrator 64 uses radial resonance to generate a therapeutic ultrasound wave with a relatively low frequency of 450 kHz in order to dissolve the thrombus 31 together with the thrombus-releasing agent. To supply the thrombus-releasing agent, an injection cannula can be inserted into the catheter 22 and the agent can be injected locally from the distal end of the catheter 22 at the thrombus position. If the thrombus releasing agent is the one that has been reported to act selectively on the thrombus, e.g. B. t-PA, it can be given according to an intra venous infusion.

The detection of the therapeutic effect, ie the detection of the solution state of the thrombus, is carried out according to one of the two following methods. According to one of these methods, the recanalization rate of the blood vessel is determined on the basis of the area closed by a thrombus, based on the cross section (ie the area of the tubular hollow body) of the sectional image of the blood vessel shown on the blood vessel B mode screen 37 . If a predetermined recanalization rate has been reached by this method, then either the further supply of the thrombus-releasing agent or the irradiation with the therapeutic ultrasound wave is stopped at the discretion of the doctor. According to another method, the blood flow in the area affected by the thrombus is determined with the aid of a colored plasmonide, and the progress of the thrombus is determined from the volume of the blood flow or from its restriction. According to each of these methods, the therapeutic ultrasound wave is generated in this embodiment based on the thrombus position. In this way, the therapeutic ultrasound wave is directed precisely and reliably to the thrombus, so that it is solved. Accordingly, this embodiment can be applied even to diseases of the coronary artery, including myocardial infarction, which is extremely critical and requires immediate treatment, with remarkable success being achieved with a significantly shorter treatment time, since the spread of the ultrasound beam through the ribs or tissue in the area the body surface is not blocked or disturbed. Furthermore, the dosage of the thrombus-releasing agent can be reduced to a minimum in order to avoid side effects.

In this embodiment, a ceramic or polymer material is used as the material of the vibrator arrangement 63 . Examples of such ceramics are ceramics based on lead zirconate titanate, lead titanate and lead metaniobate, represented by PZT, while examples of polymers are polyvinylidene fluoride (PFD), a copolymer of vinylidene fluoride (VD) and ethylene trifluoride, and vinylidene cyanide. A ceramic and polymer piezoelectric composite can also be used.

When using a polymer material for the ultrasonic transducer, this must, because it takes the form of a film, be wound on the catheter 22 , since it cannot be shaped as a vibrator arrangement. In this case, as in the fourth embodiment according to FIG. 6, an internal ultrasonic probe vibrator 70 and a reflection plate 71 can be combined; the reflection plate 71 can be rotated about the axis of the catheter 22 as indicated by an arrow 72 to perform the radial scan.

If radial scanning using continuous Doppler waves should be made and the above Reflection plate is used for transmission and Different vibrators required to receive. So you can  for example two resonators for half each Frequency are connected and as a transmitter or receiver serve.

If a viewfinder 62 , a vibrator arrangement 63 and a therapeutic vibrator 64 are formed into a piezoelectric composite, consisting of strip-shaped piezoelectric ceramics and resin made of suitable materials in each case, and alternately connected and aligned on the peripheral surface of a catheter, a single vibrator can be used Function of the viewfinder 62 , the Vibra gate assembly 63 and the therapeutic vibrator 64 take over. In this case, the dimensions of the piezoelectric composite and the piezoelectric ceramics in the respective directions can be suitably determined; the radial resonance of the entire piezoelectric composite can be used for the therapeutic ultrasound wave, the vibration in the thickness of the piezoelectric ceramics perpendicular to the arrangement direction can be used for the ultrasound wave to observe a sectional image of the blood vessel, and the resonance of the catheter can be in the axial direction can be used for the ultrasound wave to present the distal end of the catheter. In addition, a vibrator can be set so that it performs two of the functions of either the viewfinder 62 , the Vibratoranord voltage 63 and the therapeutic vibrator 64 .

Further embodiments of the present invention are described with reference to FIGS. 7 to 14.

In the fifth embodiment, an ultrasound radiator 80 for the radiation of a therapeutic ultrasound wave contains spherically symmetrically arranged piezoelectric elements, as shown in FIG. 7. An acoustic fitting layer 81 is attached to the front surface of the ultrasound radiator 80 , and on the fitting layer 81 a bellows-type water bag 82 is attached. A film 83 to be brought into contact with the body surface of a patient P is provided at the distal end of the water bag 82 .

As can be seen from FIG. 8, an ultrasound probe 21 is removably attached to the ultrasound emitter 80 by means of a probe holder 84 . A pack 87 for ensuring the watertightness of the water bag 82 and for fixing the ultrasound emitter 80 and the ultrasound probe 21 in predetermined positions is attached to the holder 84 . The package 87 contains a spring 88 on the inside of the circumference of the holder 84 and an O-ring 89 biased towards the center by the spring 88 , as can be seen from FIG. 9. If the O-ring 89 engages in a groove 21 a formed in the circumferential direction at a predetermined position of the ultrasound probe 21 , water tightness is provided, and the ultrasound emitter 80 and the ultrasound probe 21 are fixed. A water inlet opening 85 and a water outlet opening 86 are provided for the water bag 82 . Water is supplied to or removed from the water bag 82 via the water inlet or outlet opening 85 or 86 in order to regulate the amount of water in the water bag 82 . After that, the bellows expands or contracts to change the distance between the ultrasound probe 21 and the body surface of the patient P, thereby changing the focus of the probe 21 in the patient's body.

Referring to FIGS. 7 and 8, the ultrasonic probe 21 is arranged in the cen tral area of the ultrasonic radiator 80th However, it can also be arranged to the side of the central area, as shown in FIG. 10. In addition, an ultrasound probe 21 can also be arranged externally on an ultrasound emitter 80 by means of a holder 84 , as shown in FIG. 11.

If an ultrasonic radiator 80 is built using a so-called. Ring-like arrangement of piezoelectric vibrators, in which a plurality of annular vibrators are arranged concentrically, as shown in FIG. 12, the focal point can be changed electronically in that the respective vibrators are out of phase can be controlled. In contrast to the above-described embodiments, it is no longer necessary to increase or decrease the amount of water in the water bag, so that the water bag can be replaced by a gel cushion. Because of this, a water treatment unit to improve functionality can be dispensed with.

In the above description, each ultrasonic radiator 80 changes the focal point in the depth direction. If a two-dimensional vibrator arrangement according to FIG. 13 is used, the focal point can be changed by electronic scanning, as a result of which the size of a gel cushion 90 can be further reduced and the functionality can thus be improved.

The waveform of the driver signal supplied by a radiator control circuit 38 to the ultrasonic radiator 80 according to FIG. 7 can be selected according to the respective purpose from an undamped wave, a burst wave and a pulsed wave; see Figures 14 (a) through 14 (c). If, for example, the thrombus-infested area forming the treatment target is relatively flat and no tissue, e.g. B. bones or lungs are present, which cause a strong reflection of the ultrasonic wave and thus generate heat, an undamped wave is used. If the thrombus-affected area is deep and there is a bone or the like in the propagation path of the therapeutic ultrasound wave, so that each wave requires a comparatively high energy, a pulsed wave is used. In this way, the waveform of the drive signal for the ultrasound emitter 80 can be suitably selected according to the respective treatment conditions.

It is again referred to Fig. 7, according to the fifth embodiment in a quantitative calculation circuit 91 for the therapeutic effect with a blood vessel-B-Mo dus imaging system processing circuit 36 is connected. The calculation circuit 91 determines the cross-sectional area of the blood vessel and the area of an area of the blood vessel that is recanalized in the course of the dissolution of the thrombus, based on the image data of the blood vessel cross-section, which is generated by the blood vessel B-mode image system processing circuit 36 by image processing are determined, from which the recanalization rate is calculated. The calculated recanalization rate is transferred to a blood vessel B mode screen 37 and is displayed there in numerical form.

The recanalization rate is compared by an identification circuit 92 with a predetermined threshold value. If the recanalization rate exceeds the threshold value, this means that the blood vessel is again sufficiently continuous and the treatment is complete; the radiation control circuit 38 is deactivated so that the radiation of the therapeutic ultrasound wave is set. In the fifth embodiment, when the identification circuit 92 determines the end of the treatment, a solvent injection control unit 93 is switched off, whereby the injection of the solvent from an injection opening 94 in the distal end region of a catheter 22 into the blood vessel is ended. The solvent injection control unit need not necessarily be of the type in which the agent is injected from the distal end of the catheter, but can also operate on the infusion principle.

FIG. 15 shows examples of display outputs on a fabric screen 29 and a blood vessel-B-mode screen 37th The tissue screen 29 shows a B-mode image 11 from inside the patient P. The blood vessel B-mode screen 37 shows an image 12 of the cross section through a blood vessel and the re-channeling rate identified by reference number 13 . Since not only the tomographic B-mode image 11 , but also the blood vessel sectional image 12 and the recanalization rate 13 are output on the screen, it is possible in this way to determine the extent of the recanalization of a blood vessel that results from the M mode. Image is difficult to determine and can only be confirmed by X-rays, clearly and quantitatively, which allows conclusions to be drawn about the treatment effect. If, in particular, the recanalization rate is determined quantitatively by the calculation circuit 91 and compared with the threshold value by the identification circuit 92 , the thrombus-releasing treatment can be set automatically, as described above.

In this embodiment, sectional image data of the blood vessel are acquired in order to be able to determine the recanalization status of the blood vessel. However, a Doppler catheter may be required to measure the blood flow, ie to confirm whether the blood vessel is clear again or not. In this case, if the numerical display 14 'of the flow rate is added to a B-mode tomographic image 11 as shown in Fig. 16A, or if a bar chart is output as shown in Fig. 16B, an operator can easily see the therapeutic effect determine.

According to the present invention, the thrombus can Be confirmed by the tomographic image of the area Inside the patient's body by the first ultrasound imaging device is shown; the status of the thrombus Solving treatment is determined by the second Ultrasound imaging device the tomographic image of the Blood vessel. It is therefore possible to have one therapeutic ultrasound wave precisely on the to radiate the thrombus-infested area, so as to to strengthen therapeutic effect, and after sufficient Solution of the thrombus the excessive supply of the to prevent thrombus dissolving agents, so as to avoid undesired Avoid side effects.

A value, e.g. B. a blood vessel recanalization rate that the Effect of the thrombus-releasing treatment is represented determined by calculation. If this value is one has reached the specified value, the radiation of the therapeutic ultrasound wave from the ultrasound emitter set and also the injection of the thrombus solvent terminated in the blood vessel, d. H. the Be action is automatically canceled when the thrombus is sufficiently solved. The result is a more effective treatment with fewer side effects possible.

Furthermore, one emanating from the ultrasound probe therapeutic ultrasound wave and thus the position of the Catheter from the Ultra inserted into the blood vessel sound converter recognized; the results in this regard in the screen output the tomographic image from the The patient's body superimposed so that it is established can be whether the catheter is correctly in the thrombus an area was introduced or not. In this case a strip-shaped piezoelectric element so turned on that it performs two functions, i. H. to the one a monitoring function with respect to the tomographi  image of the blood vessel and on the other hand a function to identify the catheter position by the appropriate choice the dimensions of that used for the ultrasonic transducer strip-shaped piezoelectric element. This results in a smaller size of the converter, which is a can be attached to the catheter in multiple ways.

Claims (12)

1. Thrombus-releasing treatment device for dissolving a thrombus by radiating a therapeutic ultrasound wave onto a thrombus-affected area inside a blood vessel into which a thrombus-releasing agent is injected, characterized by :

• - An ultrasound emitter ( 20 ) for radiating a therapeutic ultrasound wave into the thrombus-affected area;
• - An ultrasound probe ( 21 ) for recording tomographic image data from inside a patient;
• - a first ultrasound imaging device ( 41 ), which is connected to the ultrasound probe ( 21 ), for the visual output of the tomographic image data supplied by the ultrasound probe ( 21 );
• - A catheter ( 22 ) inserted into the blood vessel;
• - An ultrasound transducer ( 23 ) provided for the catheter ( 22 ) for capturing tomographic image data from inside the blood vessel; and
• - A second ultrasound imaging device ( 42 ) which is connected to the ultrasound transducer ( 23 ) for visuel len output of the ultrasound transducer ( 23 ) delivered tomographic image data.

2. Thrombus-releasing treatment device for dissolving a thrombus by radiating a therapeutic ultrasound wave onto a thrombus-affected area inside a blood vessel into which a thrombus-releasing agent is injected, characterized by:

• - An ultrasound emitter ( 20 ) for radiating a therapeutic ultrasound wave into the thrombus-affected area;
• - An ultrasound probe ( 21 ) for recording tomographic image data from inside a patient with the aid of an ultrasound wave with a predetermined frequency;
• - a first ultrasound imaging device ( 41 ), which is connected to the ultrasound probe ( 21 ), for the visual output of the tomographic image data supplied by the ultrasound probe ( 21 );
• - A catheter ( 22 ) inserted into the blood vessel;
• - A provided for the catheter ( 22 ) ultrasonic transducer ( 23 ) for detecting tomographic image data from the inside of the blood vessel by means of an ultrasonic wave, the frequency of which is different from that of the ultrasonic probe ( 21 ), and for demodulating the ultrasonic wave from the ultrasonic probe ( 21 );
• - A second ultrasound imaging device ( 42 ), which is connected to the ultrasound transducer ( 23 ) for the visual output of the tomographic image data provided by the ultrasound transducer ( 23 );
• - A position detector device ( 33 ), which is connected to the ultrasonic transducer ( 23 ), for processing a demodulation signal of an ultrasonic wave from the ultrasonic probe ( 21 ), which is offset by the ultrasonic transducer ( 23 ), whereby a position of the catheter ( 22 ) can be recognized is; and
• - A device for outputting a detection result of the position detector device ( 33 ) on a screen of this first ultrasound imaging device.

3. Apparatus according to claim 2, characterized in that the ultrasonic transducer ( 23 ) has at least one strip-shaped piezoelectric element ( 24 ) which is arranged in the longitudinal direction of the cathode ( 22 ), with this piezoelectric element having a thickness with a length in the circumferential direction of the catheter (22) and a length in the axial direction of the catheter (22) any two of these dimensions of a frequency of the ultrasonic wave for acquiring the tomographic image from the interior of the blood vessel as well as a frequency of the ultrasonic wave corresponding to the probe by the ultrasound ( 21 ) is used to acquire the tomographic image data from inside the patient's body. 4. The device according to claim 3, characterized in that the remaining of the three dimensions of the piezoelectric element ( 24 ), the thickness, the length in the circumferential direction of this catheter and the length in the axial direction of this catheter, a frequency of the ultrasonic wave emitted by this ultrasound emitter corresponds. 5. Device according to one of claims 1 to 4, characterized in that the ultrasound emitter ( 63 ) is arranged on this catheter. 6. Thrombus-releasing treatment device for dissolving a thrombus by radiating a therapeutic ultrasound wave onto a thrombus-affected area inside a blood vessel into which a thrombus-releasing agent is injected, characterized by:

• - An ultrasound emitter ( 80 ) for radiating a therapeutic ultrasound wave into the thrombus-affected area;
• - An ultrasound probe ( 21 ) for recording tomographic image data from inside a patient;
• - a first ultrasound imaging device ( 41 ) for the visual output of the tomographic image data supplied by the ultrasound probe ( 21 );
• - A catheter ( 22 ) inserted into the blood vessel;
• - An ultrasound transducer ( 23 ) provided for the catheter ( 22 ) for capturing tomographic image data from inside the blood vessel; and
• - A second ultrasound imaging device ( 42 ) for the visual output of the tomographic image data supplied by the ultrasound transducer ( 23 );
• - A calculation device ( 91 ) for calculating a value representing the effect of a thrombus-releasing treatment on the basis of the tomographic image data supplied by this ultrasound transducer;
• - An identification device ( 92 ) for determining whether the value has reached a predetermined value or not; and
• - A device ( 38 ) for switching off the radiation of the therapeutic ultrasound wave by the ultra sound emitter ( 80 ) when the calculated by this calculation device ( 91 ) has reached the predetermined value.

7. The device according to claim 6, characterized in that this calculation device ( 91 ) with the identification device ( 92 ) is connected, and that this device further includes an injection control device ( 93 ) which is connected to the identification device for regulating the Injecting or switching off the supply of the thrombus-releasing agent into the blood vessel on the basis of a predetermined signal generated by the identification device ( 92 ). 8. The device according to claim 6, characterized in that this ultrasound emitter ( 80 ) has spherically symmetrical piezoelectric elements that an acoustic fitting layer ( 81 ) is placed on a front surface of this ultra sound emitter that on this acoustic fitting layer ( 81 ) with a bellows-type water bag ( 82 ) is attached, and that a film ( 83 ) to be brought into contact with a body surface of a patient P is provided at the distal end of the water bag ( 82 ). 9. Device according to claim 6, characterized is that the ultrasonic probe (21) removably attached to the ultrasound emitter (80) by means of a tubular probe holder (84) and secured to the ultrasonic emitter (80) when a package (87) to ensure the watertightness of the water bag ( 82 ) and for fixing the ultrasound emitter ( 80 ) and the ultrasound probe ( 21 ) in predetermined positions in a predetermined position of the ultrasound probe ( 21 ) along a groove ( 81 ) formed in the circumferential direction, which engages by means of a Spring device ( 88 ) on the inside of the circumference of the holder ( 84 ) and by means of a ring device ( 89 ) is biased towards the center. 10. The device according to claim 6, characterized in that the ultrasonic probe ( 21 ) is arranged in the central or peripheral area of the ultrasonic emitter ( 80 ). 11. The device according to claim 8, characterized in that the ultrasound emitter ( 80 ) is constructed from a ring-like arrangement of piezoelectric vibrators, in which a plurality of ring-shaped vibrators are arranged concentrically, and that each of these vibrators changes a focal point electronically by phase-shifted control . 12. The apparatus according to claim 8, characterized in that the ultrasound emitter ( 80 ) is a piezoelectric vibrator's in two-dimensional arrangement.